A novel cone-beam CT scanning technique for measuring periodontal soft tissues in the esthetic area.

PURPOSE: This study investigated and tested a novel cone-beam computed tomography (CBCT) scanning technique capable of obtaining clear contours of soft tissues in the esthetic area. METHODS: Twenty-three periodontally healthy participants underwent this novel CBCT scanning technique. Soft tissue morphological parameters were measured on the CBCT images obtained. Intraoral clinical data were also collected at the same locations, and the accuracy of the CBCT method was tested. RESULTS: The median (interquartile range [IQR]) of the supracrestal gingival tissue thickness as 0.91 (0.73-1.13) mm, and the thickness of the central incisors was significantly greater than that of the canines (P < 0.05). The median (IQR) of keratinized tissue thickness was 0.73 (0.55-0.91) mm, which also showed a significantly greater thickness in the central incisors than in the canines (P < 0.05). Bland-Altman analysis suggested that CBCT could be accurate for measuring soft tissues in the esthetic area. CONCLUSION: The novel CBCT technique described yields clear contours of soft tissues in the esthetic area without the need for auxiliary tools. Moreover, measurements of soft tissue morphological parameters on CBCT appear to be accurate.

[Comparison of subgingival debridement efficacy of air polishing and manual scaling].

PURPOSE: To assess the efficacy of subgingival air polishing and traditional manual scaling in 3-6 mm pockets. METHODS: Patients with chronic periodontitis who were in the maintenance phase were randomly assigned to receive subgingival air polishing (experimental group) and manual scaling (control group) in 4 teeth with probing depths of 3 to 6 mm. Clinical variables including plaque index (PI), probing depth (PD), probing on bleeding (BOP) and gingival recession (GR) were recorded at baseline, 7 and 30 days post-treatment. "Pocket closure" [PD ≤ 4 mm and BOP⁻] was also calculated as supplementary data. The data of the 2 groups were compared using paired t test with SAS 8.2 software package. RESULTS: Thirty-one patients were enrolled and PI was 0.8 during the study. Both treatment procedures resulted in significant reductions of PD at day 7 (P<0.0001). BOP% had significant reduction in the experimental group at day 7 (P=0.0390), but there was no significant difference compared to baseline at day 30. Meanwhile, BOP% in the control group demonstrated downward trends during the study, and significant improvement at day 30. The percentages of sites of "pocket closure" significantly increased in both groups (P=0.0329 and P=0.0035, respectively). CONCLUSIONS: The study indicates that subgingival air polishing and traditional manual scaling are both effective for improving clinical variables during supportive periodontal therapy (SPT) in teeth with probing depths of 3 to 6 mm. But the results reveal no significant difference between the 2 modalities.

[The effect of vascular endothelial cells on the migration of periodontal ligament cells and gingival fibroblasts].

PURPOSE: To investigate the effect of human vascular endothelial cells (HUVEC) on the migration of human periodontal ligament cells (HPDLC) and human gingival fibroblasts (HGF) through a model mimicking periodontal wound healing or regeneration. METHODS: HUVEC, HPDLC and HGF were co-cultured using a Transwell system, while HPDLC or HGF was cultured independently as control. Chemotaxis assay was performed using cell culture inserts (0.8µm pore size) to assess the effect of HUVEC on HPDLC and HGF vertical migration at 24h. A scratch wound assay was performed to assess the effect of HUVEC on HPDLC and HGF horizontal migration at 0 h, 8 h, 16 h and 24 h. A round glass sheet assay was performed to assess the effect of HUVEC on HPDLC and HGF wound healing ability at 1d, 4d and 7d. The data was processed with SPSS 13.0 software package. RESULTS: At the round glass sheet assay, while HUVEC was present, the integrated option density (IOD) of HPDLCs and HGFs were significantly higher than each of the single culture (P<0.01). Results of chemotaxis assay and scratch wound assay showed that the cell number of HPDLCs and HGFs were significantly higher than each of the single culture while HUVEC was present (P<0.01), and the number of PHDLCs was significantly higher than HGFs on chemotaxis assay (P<0.01) but the result of scratch wound assay was on the contrary (P<0.01). CONCLUSIONS: The presence of HUVEC can promote migration of periodontal cells, and the effect is more prominent on HPDLC than on HGF in vertical migration and wound healing, while horizontal migration is more prominent on HGFs as contrast.